477741-39-2Relevant academic research and scientific papers
Synthesis of β-substituted α-amino acids with use of iridium-catalyzed asymmetric allylic substitution
Kanayama, Takatoshi,Yoshida, Kazumasa,Miyabe, Hideto,Kimachi, Tetsutaro,Takemoto, Yoshiji
, p. 6197 - 6201 (2007/10/03)
The asymmetric synthesis of β-substituted α-amino acids with use of iridium-catalyzed allylic substitution was described. The Ir-catalyzed allylic substitution of diphenylimino glycinate with allylic phosphates proceeded smoothly even at 0 °C and gave branch products with high enantioselectivity (up to 97% ee), when chiral bidentate phosphite bearing the 2-ethylthioethyl group was employed. In addition, both diastereomers of the branch products were synthesized stereoselectively by simply switching the base employed. These methods were also applied to the asymmetric synthesis of quaternary α-amino acids.
Enantio- and diastereoselective Ir-catalyzed allylic substitutions for asymmetric synthesis of amino acid derivatives
Kanayama, Takatoshi,Yoshida, Kazumasa,Miyabe, Hideto,Takemoto, Yoshiji
, p. 2054 - 2056 (2007/10/03)
Simply switching the base employed in the first enantioselective allylic substitutions of diphenylimino glycinate 1 with 2, which are catalyzed by an Ir complex of chiral phosphite 5, allows the two branched diastereomers 3 and 4 to be selectively synthes
Pd-catalyzed asymmetric allylic alkylation of glycine imino ester using a chiral phase-transfer catalyst
Nakoji, Masayoshi,Kanayama, Takatoshi,Okino, Tomotaka,Takemoto, Yoshiji
, p. 7418 - 7423 (2007/10/03)
Pd-catalyzed asymmetric allylic alkylation of the glycine imino ester 1a has been developed using a chiral quaternary ammonium salt 3d without chiral phosphine ligands. The proper choice of the achiral Pd ligand, P(OPh)3, is important to achieve high enantioselectivity. By this method with the dual catalysts, numerous enantiomerically enriched α-allylic amino acids 4a-h could be prepared with comparable to higher enantioselectivity than that of the conventional asymmetric alkylation of 1a. In addition, the Pd-catalyzed reaction of 1a with 1-phenyl-2-propenyl acetate 2i afforded the branch product 6 with high enantio- and diastereoselectivity (>95% de, 85% ee).
